Mark Swinney Jr., 14, died at the scene and 52-year-old Donald Swinney died later at a hospital, The Courier-Journal reports.

Officials say the group rented the pontoon boat at around 8pm on Independence Day and the incident was reported just before 9.30pm as revelers gathered along Waterfront Park for the 4th of July festivities.

Dead: Donald Swinney, 52, and Mark Swinney Jr., 14, died Saturday after a 24-foot pontoon boat (pictured) they were riding in, along with seven others, hit a barge and capsized in the Ohio River

Rented: Officials say the group rented the pontoon boat at around 8pm on Independence Day and the incident was reported just before 9.30pm

Frederick told CNN that Louisville Fire Department responders arrived at the scene to find the boat pinned against a work barge in the middle of the river.

Four people -- three children and one adult -- were rescued and taken to a hospital.

The three children were sent to Korsair Children's Hospital and are in stable condition, the adult's condition is unknown, WAVE reports.

Two adults and a girl remain missing. Fire officials and other responders searched both the Louisville and Indiana sides of the riverfront Sunday.

The search continued Monday.

Gathered: Friends gathered on the wharf under the Second Street Bridge on Monday as they waited for word on the three missing people

'The issue is if someone has a flotation device or if they were able to latch on to something that would keep them afloat there is potential were they could be further downstream,' Frederick said.

'There is also the tragic issue that they may have drowned, and it would be difficult to locate them,' said Frederick.

The department was assisted by the Harrods Creek Fire Department, the Louisville Metro Police Department, the Clarksville Fire Department, the Jeffersonville Fire Department, and the New Albany Fire Department

Frederick says the current of the Ohio River was too swift to send dive teams into the water, leaving crews left to search for the missing on the surface of the water.

'There are entire trees ... floating down at a rapid rate of speed,' he said. 'We just don't think it's safe to put divers in.'

However, two law enforcement drones with thermal imaging flew above the scene, CNN reports.

A helicopter flew above the scene and agencies from Kentucky and Indiana, including the coast guard, responded to the incident.

Frederick told ABC News that there was no indication that alcohol or foul play was involved.

The department was assisted by the Harrods Creek Fire Department, the Louisville Metro Police Department, the Clarksville Fire Department, the Jeffersonville Fire Department, and the New Albany Fire Department.